Conventionally, when controlling driving of respective motors in a motor system configured such that a plurality of motors is to be controlled by a control function, a large amount of wiring such as a power supply, a signal cable, a power line to the motor, and an encoder signal line is necessary for each motor's motor controller installed near a personal computer, a sequencer, or the like that is the control function.
FIG. 4 is a configuration diagram illustrating an example of a conventional motor system. In the diagram, the conventional motor system is configured such that motor controllers 230A, 230B, 230C, . . . for respectively controlling motors 300A, 300B, 300C, . . . are respectively connected to a serial signal generator 200 that is a personal computer or the like, each of the motor controllers 230A and the like are connected in parallel to a direct-current power supply 400, the respective motor controllers 230A and the like and the respective motors 300A and the like are connected with each other by cables 900A, 900B, 900C, . . . , and encoders 330A or the like are attached to the motors 300A and the like as appropriate and connected to the motor controllers 230A and the like and the motors 300A and the like by cables 930A and the like. The motor controllers 230A and the like are all installed in the vicinity of the serial signal generator 200, and for each of the motor controllers 230A and the like, wiring for a power supply, a signal cable, a power line to the motor, and an encoder signal line must be provided over a long distance to the motors 300A and the like that are respective control objects.
Among prior art related to configurations of such motor systems, for example, a proposal disclosed in Japanese Patent Laid-Open No. 2000-262014 (Patent Document 1) is related to a method of controlling motors integrated with amplifiers, wherein the method uses a LAN for wiring-laborsaving, and a controller and each motor integrated with an amplifier are connected by serial communication. In addition, a proposal disclosed in Japanese Patent Laid-Open No. H11-299291 (Patent Document 2) similarly reduces wiring by adopting serial communication between respective units.